Photographic processing baths, e.g. development, bleaching and fixing baths, in most cases contain the required active ingredients at a low concentration and are therefore prepared by the user himself from water and chemical concentrates and optionally other auxiliary agents.
The concentrates should be as far as possible simple to dose and substantially dust-free, and packaging and transport should not entail unnecessarily high costs.
The liquid concentrates conventionally used in practice for the preparation of photographic baths ready for use have the advantage over the previously used pulverulent products that they do not give rise to dust and are not difficult to dissolve. The concentrates have the disadvantages of containing a high proportion by weight and volume of water and being packed in bulky packages which are difficult to dispose of.
Spray dried or freeze dried products according to DE-OS 37 33 861 which are intended to avoid these disadvantages have, however, the disadvantage of producing a large amount of dust.